1. Field of the Invention
The present invention relates to electronic communication systems for determining a measurement of the distance between two objects from a position remote from both objects. In particular, the invention is directed to an electronic system and method for determining a measurement of the distance between two objects on earth, wherein the location of one of the objects is known in a location defining data and the location of the other objects is known, but not in location defining data. The invention is particularly useful for determining a measurement of the distance between a golf ball, positioned on the fairway of a golf course, and the hole or pin on a green associated with the fairway on the golf course.
2. Prior Art
In playing the game of golf on a golf course, the player is provided with the distance, in yardage, from the tee to the pin or hole on the green for the "hole" being played. For the sake of clarity, the hole on a green of a golf course will, hereinafter be referred to as pin and the hole on a golf course, which includes the tee, the fairway and the green, will hereinafter be referred to as "hole". It will be appreciated that the hole on the green receives the shaft of a flag which identifies the number of the "hole" and that the term flag, and pin, and hole on the green all relate to and identify the same point. Often the distance between the tee or tee-off point and the pin is much farther than the ball is driven with a golf club, in a single stroke. It is usual for a golfer to drive a golf ball short of the green of the "hole" being played where the "hole" is rated par four or par five, for example. Once a golf player drives a golf ball off the tee, toward the green of the "hole" being played, the golfer is essentially left on his own to determine the yardage between the golf ball, laying on the fairway, and the pin on the green of the "hole" being played.
The prior art includes devices and systems which may be used by the golfer for determining the approximate distance between the pin and a point that approximates the location of the golf ball laying on the fairway but, for the most part, the prior art does not teach apparatus which provide a precise measurement, in standard measurement terms, of the distance between a golf ball laying on a fairway and the pin on the green associated with that fairway. U.S. Pat. No. 4,136,394, issued to Josies, et al, titled Golf Yardage Indicator System, issued in 1979, teaches a multi-unit system in which a transponder is mounted on or near the pin on the green. A portable complex transmitter/receiver carried by the golf player, is used to transmit a signal to the transponder on the green and the transponder, in response, transmits a data signal that picked up by the portable receiver. The data is analyzed for determining the distance between the transponder and the portable transmitter/receiver. The data signal is in the sonic range and sonic waves are subject to variances when projected through air, such as by air temperature and humidity. Also, a golf course usually has many changes in ground elevation which may require that the transponder be mounted above the ground, such as on the shaft of the flag used to identify the hole and green. This leads to problems because the shaft/flag is often removed from the hole on the green when golf players are playing on the green. With the shaft/flag removed from the hole the transponder on longer identifies with the hole on the green.
U.S. Pat. No. 5,044,634 to Dudley, titled Golf Information System teaches burying wires of a grid in the ground of a fairway. The grid wires emit signals which are read by a receiver. However, this system does not locate a ball lying between wires of the grid which, in order to practice the invention must be buried in the fairway. In order to bury a wire grid in the fairway, the fairway must be dug up. This is extremely expensive and interferes with the use of the golf course lot playing golf. U.S. Pat. No. 5,046,839 to Krangle, titled Golf Course Range Finder System teaches a hand-held range finder device emitting light pulses that are reflected by a reflector mounted on the shaft of the flag. This system has some of the same problems attendant with the Josies, et al teaching, plus the additional problem that in order to use the Krangle system an unobstructed view of the shaft/flag is required.
U.S. Pat. No. 3,868,692 to Woodard, et al, titled Golf Yardage Finder teaches the use of a mobile receiver and a transmitter located at the green. The transmitter emits signals which are received by the receiver and the receiver, which includes a signal field strength detecting device, measures the strength of the signal and converts the signal strength into yardage between the transmitter and the receiver, using the strength of the signal. Here again, the distance measured is the distance between the components of the measuring device, the transmitter and the receiver, not the transmitter and the ball on the fairway.
U.S. Pat. No. 4,480,310 issued to Alverez, titled Dead Reckoning Range Finding Device For Cart, teaches sensing devices, attached to a golf cart, for monitoring the wheels of the cart for measuring the distance and direction traveled by the cart. The Alvarez teaching is directed to measuring the distance and direction of the ball flight rather than measuring the distance between the ball, on the fairway, and the pin on the green.
U.S. Pat. No. 4,703,444 issued to Storms, Jr., et al, titled System For Determining Distance To And Location Of Features On A Golf Course, teaches positioning three or more remote, spaced transmitters on a golf course each of which transmit signals. A portable receiver, carried by a golfer, serves as an interrogation unit, receiving signals from the transmitters and, by triangulation, locates the position of the portable receiver. The portable receiver includes a keyboard for entering requests pertaining to distances between the receiver and another point or object on the golf course. As with other prior art, Storms, Jr., et al teaches a system which measures the distance from a receiving unit, rather than measuring from the ball on the fairway.